This invention relates to a fuel supply system including a source of fuel, a fuel injection pump, and a filter interposed between the fuel source and the fuel injection pump for delivery of fuel to a diesel engine and, more particularly, to an apparatus for use in the fuel supply system between the filter and the fuel injection pump informing whether the filter is clogged to a predetermined degree.
In order to provide high accuracy required in controlling injection of fuel into diesel engines, a filter has been provided in a fuel supply line between a fuel tank and a feed pump for filtering out water and other unwanted contaminants from the fuel flowing through the filter. It is conventional practice to replace the filter after a selected operational period determinative on the total distance traveled by the vehicle. Since it is required to provide a relatively large margin in determining the operational period of the filter, the filter may be replaced wastfully although it is still usable. In addition, the filter would clog up prior to servicing due to the use of contaminated fuel, restricting supply fuel to the fuel injection pump, and thereby limiting engine output at high engine speeds.
Accordingly, it is an object of the present invention to provide an improved fuel supply system informing when the filter clogs to a predetermined degree.
Another object is to provide a water draining device for draining water filtered from fuel out of the fuel supply system.